A third of the way through Sarai Walker’s debut novel Dietland, a shadowy vigilante movement known only as “Jennifer” tosses two rapists off an overpass on to the highway, where their bodies are mangled and flattened by speeding cars. They toss an additional 12 rapists out of an airplane from a great height. They strangle the impresario of a Girls Gone Wild-type program and blow up his enabling girlfriend. They scalp a hostage, demanding that lewd images of women be removed from newsstands by his sister, a publishing mogul.

These events, when they happen, are a surprising detour from the road you think you are traveling. The novel opens on a retiring young woman named Plum, who works as an advice letter ghostwriter for the editor of a popular teen magazine called Daisy Chain. Plum mopes around her cousin’s Brooklyn apartment and a local cafe, answering torrents of mail from troubled young women and eating grim little “Waist Watchers” meals. Plum is 300 pounds, perpetually hungry, and beleaguered after years of unsuccessful attempts to whittle herself down to a pleasingly thin shape. When Dietland begins, Plum has scheduled a stomach-stapling surgery; she pre-emptively orders beautiful clothes for a much thinner person, clothes she will wear once her organs have been re-sectioned and her stomach reduced to “the size of a walnut”. Plum is lumbering through life in a lonely, dreamlike and generally dissatisfied state; things will take off, she knows, when her thin self is revealed.

The book seems at first as though it will be about one woman’s struggle with her weight, buttressed by the related struggles of her young advice-seekers – girls who cut, girls who compare their breasts unfavorably to breasts they see on TV. Suddenly, though, the narrative shifts from Plum’s first-person diary to a newsy third-person account of the aforementioned rapists sailing through the air. This abrupt change – the men’s violent end and the savagery for which it was earned – is jarring, but it also marks the point at which things get a little more interesting for Plum. When the novel resumes in her voice, she is recruited both by a radical women’s cabal called Calliope House, and a feminist double agent who staffs the enormous beauty closet at Daisy Chain. The splices from the headlines continue until it is revealed that the vigilante Amazons and Plum’s new associates may have something in common.

The writing in Dietland is functional and doesn’t call attention to itself one way or another. But the spliced-in accounts are structurally inelegant, and occasionally give the novel a patchwork quality, like an unfinished garment marked up with pins and tailor’s chalk. The marriage of gonzo satire with a more earnest heroine’s awakening was never going to be an entirely comfortable one, although it allows for great moments. Dietland’s fictional talkshow hosts, Cheryl Crane-Murphy (clearly modeled after Nancy Grace), Nedra Feldstein-Delaney and Nola Larson King, form a comic Greek chorus that echo Huxley or Waugh, if Huxley or Waugh had discovered second-wave feminism and the Health at Every Size movements.

On the Nola and Nedra Show, Nola Larson King said: “I’ve been thinking about what you said earlier, Nedra, and I agree with you. I don’t think this is terrorism or lady terrorism. Do you know what I think it is?”

“I’m dying to know,” said Nedra Feldstein-Delaney.

“I think it’s a response to terrorism. From the time we’re little girls, we’re taught to fear the bad man who might get us … Isn’t that a form of terrorism?”

“For God’s sake, Nola. You’re going to get us both fired,” said Nedra Feldstein-Delaney.

Dietland’s structural oddities notwithstanding, its message resonates. It’s vanishingly rare (in fact I can’t think of an example, although that doesn’t mean one doesn’t exist) to see a novel that looks like the much-maligned “chick lit” – and sometimes reads like it – so gleefully censorious of rape culture. If its satire is sometimes a little on-the-nose, it’s only because real life, when you are talking about female grievances, is a dog’s breakfast of things so terrible they hardly need to be satirized. And that’s just the depilatories, unguents and underwear.

It’s tempting to call the novel surreal or cartoonish, but it’s really only the violent retributions that are unrealistic – young girls and servicewomen are gang-raped in vignettes lifted wholesale from the headlines, and the suggestive images of women’s bodies targeted by Jennifer need no embellishment. As I type this review, I look up at the television and see a pair of ideal breasts displayed alluringly on a beach, the owner of which encourages me to purchase Direct TV. The last time I reviewed a book by a woman in these pages, someone tweeted “Perenial [sic] ‘pinky-in-panty’, cunt-lit! When are wimun [sic] going to be begin to see the world by other paths other [sic] than their twats!” A comment about Dietland on Goodreads expressed disappointment that Plum “turned from a hopeful dreamer into an angry, confrontational and quite unlikeable young woman”.

We are so mired in belittling speech and suggestive images of women’s bodies that it’s easy to be lulled into a sense of acclimation and normalcy. For people who aren’t familiar with the idea of rape culture and think the Blurred Lines music video is just a fun sexy time, this novel will feel hysterical, jumping as it does from a sad fat woman nervous about eating a scone in public, to a strangled porn king with his own penis in his mouth. But you never really acclimate, if your sense of your own value and worth has been irrevocably tied to these images. If you’ve lived in this culture – if you’ve ever been a young woman who is trying to eat so little or eat so much that she disappears – the jump won’t seem extreme. And you may take some cold comfort from Dietland, and its opportunities for vicarious revenge.